Device to prevent overheating of shaft bearings



P. E. BESSIERE 2,566,715

DEVICE TO PREVENT OVER HEATING OF' SHAFT BEARINGS sept. 4, 1951 Filed May 29, 1948 l H/ l WMU 2v 3 64\97 m Nm m 0,00

Patented Sept. '4511951 "''DEVIGETO "PREVENTOVERHEATINGLQF vb'SHEAFT BEARINGS to ,Soeiete. -E1e9tro :Mecaniquele linveyrongsx., Rodez,,Erancaasocietx offrano@ Claims.

l" i @The Apresent `invention relates f to the.' pmi/BC- tion g-against overheating v:of the 'bearings of f ro- "viztary shafts z and 1 more :particularly i butgnot exclusively of the bearings of electrical apparatus .r1-'such as electric. brakes, ina-which 1a? rotor, prefer- -fablywmade'of a magnetic.metalyqzrigid-:with the shaftl to be bra-keel revolves inthefmagnetic field fqrproduced'byi electro-magnets, .theflcraking effect ibeingfdue to the'parasitic: currentsY thus-generated -r in the rotor.

LIhe chief objectief imyinvention;fis-:t fprovide arldevice' for ensuring :this :protection gwhiehis "'gbettercadaptedlto. meet .thefreeluirerneni'fs-` ofpracf `lftiee thanthoseused u pztci- .this-time f.-,Acc0rdlng f .to a:- featureizof f my 1irl-.veli-,1210.11,.i'..v the shaft is provided with-meansfmade of an material T'Whnglfis,.9, good conductor offheat, forty-:passing the.vv bearing to v .beA protected in; the, fiow-gofgheat from 'the shaft toethe outside,.-wher e `it 4isfdssifff-pated into the atmosphere.

' Another feature of myf irnlentionpy.consists?l in thermallyxinsulating from: the-shaftathemortion F101' -`the' bearing that "turns together; therewith.

Preferred embodiments of the presents-fluyention Will-,be .hereinafter described, with reference to the accompanying drawings, given merely by way of example, and inwhich:

electric brake fitted with rr leans forf preventing exaggerate heating of these bearings; according to the invention.

.fj-:Fig: 2 is a section of vthegbearing of..an-electric v` `tineke: provided. with .means capable of`l preventing xaggerate..heatingpithis hearing according t0 secondembodiment, of... invention. il" Eurthermore, ..preferably,f.:these meansnhave their outer ends constituted by aring portions of large area which facilitate thermal interchanges with the surrounding atmosphere.

In the embodiment of Fig. 1, the means in question consist of a lining "I provided between shaft 2 and the portion of bearing 5 which revolves together with this shaft, this lining being made of a material which is a good conductor of heat, such as aluminium, copper, etc. Lining 'I is provided at its outer end with a disc 8 1ocated in the surrounding atmosphere, this disc being either rigid with lining 1 or Xed thereto, for instance by screwing. It is clear than an important portion of the heat flux coming from rotor l and which passes through shaft 2'to flow to the outside is conveyed through lining 1 to disc 8, without passing through bearing 5, 6, disc 8 ensuring dissipation of this heat into this atmosphere.

. If.: the metal Ofi-lining 1f18...,n0t..trcngieneligh .f .to r, support. the pressure of. ,thei bearing-S, I may interpose, betweenVv lining lA and thel portion 0f the bearing, a Sleeve-9 .Offstee1, preferablvtgm- 5 persa-steel, rigid with the limngand acting as ...a supportfor. the hearing. morder tei-,ensure iixation ,sleeve 9 ion lining. 'LI may, fQrinStance mold it iii-the. massen the l lining or meyfpfix it f on thefliningwitha forant. 10 Accordingvto la, particularly; adyantegeoin em bodiment, @15018; isfiittedwith.. iinsor. blades. l0, :Whereby; .the disc. and its.1 hlaiieswonsttutathe motorini a-fanf-which.-,b1 iws =Q91ir1g airgiorzgin- :Stance guiciedfby 4afxrsing. vl. ,Linie .frameieleng the path indicated by the arrows, .to, ,iiQW, out

- through apertures i2.

v.Con.cerningrfir'st heelcetrigbrake proventi/ith vf,theeen:eration:of. enmeansiintended; tor-jpreyent Vexaggemte:heatingwf;theteeringsf0f shaft. .it may :bel arranged-@infant .suitable mannen-for yinstanceas-indicated-ley Eig.V 1JV where this brake lincludes a rotor Irpreferablyof a-magnetic metal, for-:instance: soft :,steel, =fixed :toV brake; shaft 2. 2'5" This' shaft-is housed- .in .bearings vprovid edin; the side walls of a frame 3 insidefwhich,on'either side of rotor l, are mountedxpolespieces, 4,-which -generate `inside/rotor I ,whena excited by` anV elec- V#tric -current,ffliioucault -currents theeffect of "wh-ichi -is-` to exert astrongebraking action upon 'o wrotor It; is clearfthaty'these' Foucault .cul'rentsf: cause rotor l to beheatedxf'=-=However; the-meansrused ,forcooling down Vthe-rotor,--forinstance cooling 351 `air, streams,- oftenfdo net-prevent `transfer of a portion'- oftheheat produced in rotor 1, to shaft 2 whence this heat, in the knowndevices-1 travels toward the bearings 5 of this shaft, so that the temperature of these bearings rises higher and 40 higher.

In order to reduce heating of bearings 5 or to keep this heating within admissible limits, While permitting a rise of the temperature of rotor I, and, consequently, an increase of the power of the brake, I provide, according to the main feature of my invention, means, made of a material which is a good conductor of heat, for conveying heat from the shaft to the outside, without allowing this heat to flow through the bearing to be protected against heating.

Preferably, I dispose these means, with respect to the direction of flow of the calories through the shaft toward the outside, on the upstream side of the bearing to be protected and these means are so shaped as to convey heat to the i vention.

` 3 outside along a path which avoids the bearing to be protected.

According to another feature of my invention, I thermally insulate from shafts 2 the portion 6 of the bearing which revolves together therewith. If the above first feature of the invention is used simultaneously, this insulation is, of course, between lining 1 or any other equivalent element which is a good conductor of heat and the fixed portion 6 of the bearing.

For instance, as shown by Fig. 2, I place the portion 6 of the bearing between two annular pieces I3, I 4 each of angular section and the part of which that extends at right angles to the axis of revolution of shaft 2 has a section the outer portion of which is of angular shape. Bearing element 6 and annular pieces I3, I4 are enclosed in a cage constituted for instance by two elements I5, I6, a layer I1 of a matter which is a bad conductor of heat, such as mica,

asbestos or the like, being interposed between this cage and pieces E, I3, I4. Cage I5, I6, the

It is clear that, in the construction shown `by Fig. 2, layer 17 thermally insulates the bearing with respect to shaft 2.

If cage I5, I6,- or fat least the element I of this cage is made of .a metal which is a good conductor of heat and if this element I5 is connected with an external part capable of dissipating heat into the surrounding atinosphere, the construction carries out both the first and second features of my in- However these two features may be used separately.

In a general manner, while I have, in the above description, disclosed What'I deem to be practical and efficient embodiments of the present invention, it should be well understood that I do not wish to be limited thereto as there might be changes made in the arrangement, disposition and form of the parts Without departing from the principle of the present invention as comprehended within the scope of the accompanying claims.

What I claim is:

1. An an apparatus, in combination, a bearing, a shaft supported in this bearing and subjected in operation to a heating .action on one side of said bearing, a lining of a metal which is a better conductor of heat than that of said shaft interposed between said shaft and the portion of said bearing that revolves therewith, and a disc in contact with said lining onthe other side of said bearing for dissipating heat into the atmosphere.

2. A combination according to claim 1 further including blades carried by said disc.

3. In an apparatus, in combination, a bearing, a shaft supported in this bearing and subjected in operation to a heating action on one side of said bearing, a lining of a metal which is a better conductor of heat than that of said shaft interposed between said shaft and the portion of said bearing that revolves therewith, and heat radiating means in contact with said 1ining on the other side of said bearing for dissipation of heat into the atmosphere. y

4. In an apparatus, in combination, a bearing, a shaft supported in this bearing and subjected in operation to a heating action on one side of said bearing, a lining of a metal which is a better conductor of heat than that of said shaft interposed between said shaft and the portion of said bearing that revolves therewith, heat radiating means in contact with said lining on the other side of said bearing for dissipation of heat into the atmosphere, and means for thermally insulating from said shaft the portionof said bearing that revolves together with said shaft.

5. In an apparatus, in combination, a bearing, a shaft supported in this bearing and subjected in 'operation to a heating action on one side of said bearing, said bearing including an inner raceway element revolving together with said shaft, two annular pieces fitting each on one side face of said bearing element and on a portion of the inner face thereof, said pieces having bevel-shaped outer side faces, a layer of an insulating material surrounding both ofv said annular pieces on the inner and side faces thereof, a metal cage interposed between said layer` PIERRE ETIENNE BESSIERE.

REFERENCES CITED The following references are of record the file of this patent:

UNITED STATES PATENTS Number Name Date 1,152,681 Wieselgreen Sept. 7, 1915 1,579,798 Vail April 6," 1926 2,202,424 Hough May '28, 1940 2,223,847

Engdahl s- Dec. 3;' 1940 

